[Rules] 8.4 Elevation makes no sense to me

[russ]

I am new to PG. Most of the rules seem pretty clear to me, but section 8.4 Elevation makes no sense at all to me.

8.4 Elevation

The map contains lines indicating changes in elevation. Each line represents an elevation change of 20 meters. The LOS between two hexes is blocked if it passes through one elevation line (or other elevating terrain like a town, 8.42) that is higher than both hexes.

If the LOS crosses just one elevation line, let's say "20", then one hex is necessarily at height 0 and the other hex is necessarily at height 20, right? So how could the elevation line be higher than both hexes? It seems like this sentence is describing a LOS-blocking condition which is logically impossible.

Code:

a
22  b

Here hex a is on a 20-hill and hex b is at height 0, so the LOS crosses a 20-contour, of course. How could a and b both be lower than 20 if a 20-elevation line is crossed?

Or does "one elevation line" mean "AT LEAST one elevation line" = "AN elevation line"?

It is also blocked if it passes through two elevation lines of equal height and one of the hexes is lower than both elevation lines.

If the LOS crosses 2 elevation lines of equal height, let's say "20", then if one hex is lower than 20, then necessarily it's at 0, and necessarily both hexes are in fact at 0, right?

Does sentence this mean "exactly two" or "at least two"? If "exactly two", then at least I understand why the LOS would be blocked: there's a hill between the 2 hexes:

Code:

a 2222 b

(here hex a & hex b are at height 0 and don't have LOS over the 20-hill)

But if it means "at least two", then it's less clear. It implies that a 20-high hill would block LOS between a 0-height hex and a 40-high hill, e.g.

Code:

a
44
2222 2       b

Here hex a atop the 40-hill can't see hex b because of the tiny intervening 20-hill (which creates 2 elevation lines of equal height - in total, one 40-line and 3 20-lines are crossed)?

Yet in a similar example where there is no intervening gap between the 40-hill and the 20-hill:

Code:

a
44
222222      b

Here hex a can see hex b because there's not a separate 20-hill in between (so in total, one 40-line and one 20-line are crossed - there are no 2 lines of equal elevation crossed)?

This all makes no sense to me.

Would anything go terribly wrong if I just used the elevation LOS rules from Combat Commander or Fighting Formations?